FocusPlus

FocusPlus is a productivity tool designed to help users stay focused and manage their time effectively.
Inspired by the Pomodoro technique, it features customizable timers and non-blocking notifications, so you don't have to break your flow. It will just gently reminds you every 10 minutes that you should take a break.

So you can keep your flow going without burning out.

Oh, and the UI is very clean!